Return bend fitting for oil stills



Nov" 21, 1933- F. c. FANTZ 1,936,386

RETURN BEND FITTING FOR OIL STILLS Filed Jan. 7, 1932 2 Sheets-Sheet l F/G. II 2 2} INVENTOR? W ATTORNEY Nov. 21, 1933. FANTZ 3336,38

RETURN BEND FITTING FOR OIL STILLS Filed Jan. '7, 1932 2 Sheets-Sheet 2 INVENTOR Aa M ATTORNEY Patented Nov. 21, 1933 UNITED STATES PATENT OFFICE 3 @laiins.

This application is a continuation in part of Serial No. 392,518.

It is well known in this industry that the tubes in oil stills are subject to tremendous heat and pressure. Moreover that it is highly important that an inspection of the tubes be made at frequent intervals and also that they sag or bow and if they can be turned over it will increase the life of the tube so that it will serve for a longer period of time.

In a refinery apparatus of this kind operation of the still causes an accumulation coke to be deposited on the inside of the tubes. This coke has to be removed from the interior of the tubes and this necessitates the shut-down of the still for the cleaning is usually accomplished by rotary tube cleaners inserted into the tubes after the return bend has been removed. The shut-down time is very expensive and as a consequence anything which will shorten the time of the shutdown possesses great utility.

Owing to the high pressure and temperatures to which these tubes and return bends are subjected it has long been the custom to roll the tubes into the return bends with the result that when one tube becomes damaged in use, the connected tube has to be out 01f in order to remove the damaged one. Moreover these tubes are placed in nests or banks so that their centers are exceedingly close, this condition greatly affects the type of return bend which can be employed.

My invention has for its object to provide a construction for a return bend in which the tubes may be mounted so that either one can be quickly and easily removed.

A return bend of this type is fully described in my Patent No. 1,752,331. In this patent the housing for the return bend is formed in one piece as the tubes are demounted but it has been found desirable in some instances to have the housing made in separate pieces which afterwards may be bolted together or secured in any other desired manner therefore, tubes may be mounted in either one of the conventional manners, viz., such as shown in my Patent No. 1,757,331, or rolled in, as shown in patent to Stewart, No. 1,859,850. In both cases the shoulders on the annular sections interlock with those on the tubes in the one case, through a bushing in the other by direct contact.

A further object of my invention is to construct a sectional housing so formed that the two sections can be secured together so that even if the tubes are rolled in a single tube may be removed without disturbing the adjacent one.

My means of accomplishing the foregoing objects may be more readily understood by having reference to the accompanying drawings, which are hereto annexed and made a part of this specification, in which- Fig. 1 is a side elevation partly in section of my improvement;

Fig. 2 is a cross section on the lines 2-2 in Fig. 1; the tubes and return bend.being made for the sake of clearness, one of the tubes at the left of the view is indicated in dotted lines;

Fig. 3 is a section taken on the line 3-3 in Fig. 2;

Fig. i is a top or plan view of a modified form of my invention;

Fig. 5 is a side elevation of the same partly in section, a portion of one of the side walls being. broken away to show the interior construction; and

Fig. 6 is a fragmentary detail view showing the method of fastening the housing sections together.

Similar reference numerals refer to similar parts throughout the entire description.

As shown in the drawings, my invention comprises a return bend 1 which is of conventional shape with the exception of the fact that it is preferably provided with abutments 2 and 3 formed on its external walls, the purpose of which will be hereinafter explained.

The return bend 1 is mounted in a sectional housing which consists of continuous annular portions 4, the external walls of which are provided with shoulders 7. Still tubes 5 and 6 (a fragmentary portion only being shown) are also provided with shoulders 8 adjacent their ends. These shoulders 8 are adapted to interlock with the shoulders 7 formed on the inner walls of the annular portions 4 of the housing sections. A sectional metal ring or bushing 9 may be inserted between the shoulders 8 of the tubes and the shoulders 7 on the wall of the housing sections or, as pointed out, this may be omitted and the tubes rolled into the housing. In some cases the bushings may comprise semi-circular forks 10 having extensions 11 which are bolted together, one of which extensions is preferably provided with a slot and the other with a registering'aperture, for the reception of a bolt 12 which is secured in place by means of a nut 13. The annular portions 4 of the housing may be provided with laterally extending webs 14 as shown in Figs. 4 and 5 which may abut and which are provided with grooves which extend longitudinally of the axis of the pipes. These grooves may, if

desired, by dovetail as shown at 15, adapted to be engaged by a means 16 which 'is fitted thereto and which serves to hold the sections of the housing together and operates to hold the parts in assembled position. If desired, these webs may be formed as shown in Fig. 6 and a through bolt 17 inserted therein. It will be apparent from the foregoing description that either of the tubes 5 and 6 can be removed from the housing. Obviously if the other conventional type of attaching the tubes, i. e., rolling, be employed, the defective tube may be removed without reference to its adjacent tube. The annular members 4 are provided with upwardly extending side walls 18 and 19 which carry plates 20 mounted in slots 21 adjacent the top of the said walls 18 and 19, set screws 22 are mounted in these plates 20, the inner ends 23 of which contact the abutments 2 and 3 formed on the external walls of the return bend l. The ends 24 of the still tubes are machined so that they are convex in cross section and are adapted to enter V-shaped grooves 25 formed in the faces 26 of the return bend 1 so that by tightening the set screws 22 the face 26 of the return bend and the ends 24 of the tubes are drawn into a leak-proof joint. It will be apparent from the foregoing description that this construction permits the quick removal of the return bend from the housing for the purpose of gaining access to the tubes for the insertion of a rotary tube cleaner and also if the tubes are demountable permits the tubes to be removed for inspection, replacement, or removal to a less hazardous part of the bank without having to destroy the adjacent tube.

Having described my invention what I regard as new and desire to secure by Letters Patent, is:

1. In a refinery apparatus, means for connecting a conventional return bend to a pair of still tubes to provide a passageway therethrough said tubes having outwardly projecting shoulders one on each tube adjacent the end thereof, a sectional housing, each section comprising an annulus. the walls of which have shouldered portions adapted to interlock with the shoulders on said still tubes, means carried by said housing sections for holding said still tubes and said return bend against relative longitudinal movement, the tube encircling portions being provided with grooves polygonal in cross section disposed longitudinally of the axis of the tubes, and means fitted thereto which holds the parts in assembled position.

2. In a refinery apparatus, means for connecting a conventional return bend to a pair of still tubes to provide a passageway therethrough said tubes having outwardly projecting shoulders one on each tube adjacent the end thereof, a sectional housing, each section having a substantially circular opening therein, the walls of which have shouldered portions adapted to interlock with the shoulders on said still tubes, means carried by said housing sections for holding said still tubes and said return bend against relative longitudinal movement, the tube encircling portions of said housing having abutting portions, there being grooves formed therein and a key which fits said grooves to hold the housings together and hold the parts in assembled position.

3. In a refinery apparatus, means for connecting a conventional return bend to a pair of still tubes to provide a passageway therethrough said tubes having outwardly projecting shoulders one on each tube adjacent the end thereof, a sectional housing, each section having a substantially circular opening therein, the walls of which have shouldered portions adapted to interlock with the shoulders on said still tubes, means carried by said housing sections for holding said still tubes and said return bend against relative longitudinal movement, the tube encircling portions of said housing having abutting portions, there being grooves formed therein and a dovetail key which fits said grooves to hold the housing together and hold the parts in assembled position.

FRED C. FANTZ. 

